In modern warfare, missiles and bombs often implement explosive payloads detonated upon impact at a target, or at a related time and/or place. These payloads often involve combustion, and, therefore, the use of an oxidizer.
Certain missile and bomb systems, such as “fuel-air” and other thermobaric systems, spread explosive material into the atmosphere surrounding or within a target, to strengthen and/or extend an explosive impact. Typically, these systems use primary and secondary charges, where the primary charge serves to inject and/or spread explosive material into ambient air at the target, after which the secondary charge ignites the resulting mixture. Thermobaric bombs may amplify and extend the impact of an explosive payload generally, and may aid in overcoming obstacles, such as bunkers or other enemy cover.
Some missiles, such as ramjet missiles, involve air intake to aid in powering flight. Such missiles may operate at high speeds, including supersonic speeds, and may implement variable-inlet chins. See, e.g., U.S. Pat. No. 5,167,249. In these applications, the size of an air inlets may be varied to optimize air shock, efficiency and flight power.
Some projectiles predate humanity by millions of years, arising by evolution in the animal kingdom. For example, the Archerfish fires droplets of water at small insects, arachnids and lizards from a range of up to three meters, capturing them from plants overhanging its habitat. Archerfish evolved in the Eocene epoch, about 50 million years ago—long before humans existed, let alone developed projectile firing mechanisms. Some New World Tarantulas fire hairs from their abdomen as a defense mechanism. Even plants, like the Orange Jewelweed, Peet Mosses and Scotch Broom have evolved projectile firing mechanisms, to spread seeds.
Trace evidence is any residual material from the contact or presence of a person or object at a crime. Most if not all contacts between two materials will leave some trace evidence. Modern law enforcement may develop trace evidence by shaking, batting or scraping clothing worn by a victim, or other materials left about a crime scene, collecting the dirt, dander, blood, lint that falls off, and then analyzing it in a laboratory. DNA can sometimes be recovered and analyzed from trace evidence, using an amplifier, such as PCR, to reproduce much larger amounts of the genetic material. Simpler trace evidence, such as a victim's skull with blunt force trauma, has probably been used in some form by primitive law enforcement since the dawn of civilization.